In this study, we reviewed characteristic diagnostic findings of vascular diseases in the central nervous system with 3-dimensional computed tomographic angiography (3D-CTA) using multi-detector row computed tomography (MDCT) and a novel 320-row area detector CT (320-ADCT). With coverage of 160 mm in a single rotation, 320-ADCT enables acquisition of both 4-dimensional CT angiography (dynamic 4D-CTA) and whole-brain CT perfusion imaging. We describe our experience of investigating cerebrovascular diseases with MDCT and 320-ADCT, as well as several postprocessing techniques to acquire images useful for diagnosis, therapy planning, and simulation of neurosurgical and endovascular intervention. 3D-CTA demonstrates has high accuracy in detecting and evaluating cerebral aneurysms and steno-occlusive diseases. Angiographic analysis, including information of surrounding tissues on 3D-CTA, allows assessment of the feasibility of neurosurgical or endovascular approaches and the technique to accomplish the therapy. However, 3D-CTA using MDCT is limited in its detection of aneurysms less than 3 mm in size and aneurysms embedded in the skull base region. In addition, discrimination between intradural paraclinoid aneurysms and extradural intracavernous aneurysms remains an unresolved problem in imaging of cerebral aneurysms. 320-ADCT may solve this problem with its high accuracy in discriminating arteries from the venous system. 3D-CTA could be used as an alternative to DSA for detection of severe carotid artery disease. 3D-CTA enables measurement of the lesions, plaque imaging, prediction of anatomical variants, screening for asymptomatic vascular lesions, and exclusion of patients with risk factors from carotid endoarterectomy (CEA) or carotid artery stenting (CAS). The diagnosis of intracranial dural arteriovenous fistula (DAVF) with CTA is challenging. Recently, several authors proposed diagnostic findings of ADVF by CTA and reported high sensitivity and specificity. 320-ADCT may offer comprehensive information for diagnosis and therapy planning of intracranial DAVF. Although DSA is a standard modality to detect spinal vascular malformations, selective catheterization requires considerable time and a certain amount of contrast medium, and is associated with a risk of neurological complications. Spinal 3D-CTA prior to DSA is useful in selective catheterization to arteries at certain spinal levels as well as when considering treatment options and therapy planning.